Ignition device



Patented Aug. 31, 1926.

A'lEN'l' CLARENCE 1V. BARNES, OF SIOUX CITY, IO\XA.l

GNI'AIION DEVICE.

Application filed March 2, 1925.` Serial N'o. 12,559.

.lily invention relates to an ignition device combining the functions of the ordinary spark plug and timing and distributing` mechanism commonly used in the internal 5 combustion engine.

ldy invention embodies, generally, a firing pin extended through the'engine housing of an internal combustion engine mounted 'tor longitudinal sliding Vmovement in suitably insulated bearings, adapted to move to p roximity with a stationary electrode at one eX- tromity ot its sliding path so as `to produce a. spark at that point, actuated by `a revolving cam cai'ied by the ordinary valve actuating shaft, or by an auxiliary cani ien in a similar manner to the ordisha rt dr fier it has moved. to a point within a radius from 'the stationary elecrode, triereby insuring accuracyo't timing.

lv'lore specifically, referring to the preceding object, it is my purpose to provide a tiring piu actuated by a cam which has a l lace insulated during a portion of its periphery from the cam shaft, and having a portion oit its tace in electrical connection -.h thecani shalt, the latter portion being ened to establish circuit through the the firing pin has reached :i ce predetermined proximity to the ionary electrode.

Another ohioct is to provide means with sich a tiring pin for advancing or retarding the timing ot the spark from the dash ot' an automobile embodying my invention.

,fr further object is to provide suitable means lior mounting the tiring pin in an en gine housing so to allow removal thereof, to provide for spring pressure to maintain constant contact or the firing pin with the cam, to allow adjustment of such spring pressure and to providea semi-permanent shell extendingthrough the water jacket to protect the liring pin from the water, and to prevent leakage or the water when the firing pin is removed.

TW ith these and other objects in view., my invention consists in the construction, arrangement and combination oi the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in myclaims and and illustrated in the accompanying drawings, in which: A

Fig. 1 is a transverse sectional view through a portion oit the engine with my inf vention embodied therein, the ligure being partly diagrammatic to illustrate the elecl-v trical circuit employed in lmy invention.

Fig. 2 is an elevation of a portion of the engine heard, illustrating the spark advancing and retarding mechanism.

Fig. 8 is an elevation of the lower pori ion ol" the engine housing, a. portion thereoil be ing broken away to illustrate the cam shattt Fig. d is a partly sectional, partly diagrammatical view, illustrating a somewhat modilied form of my invention.

l have used the reference character l() to indicate the water acket oit an engine hous ing. The wall ot the cylinder is'indicated at l1 and the cam sha'ft housing at 12. rlhe cylinder head, 13, is provided with the combustion chamber space, let, into which is ordinarily extended a spark plug.

lt will be vunderstood that the ktype ot motor illustrated is the ordinary 'Il-type, but that my invention could be adapted to other types oit engine.

A cam shaft, 18, is journaled in the housing, 12, The cam shaft, 18, may beV driven similarly to the ordinary cam shaft, or may be embodied in the ordinary cam shaft, and

the details of the driving mechanism are therefore not illustrated;

For each cylinder, ll, l provide onev of the tiring devices, which is preferably situated between the exhaust and intake valves ol. the respective `cylinders so as to be centered laterally relative to the respective cylinders.

The position ot the cam relative to the valve-V operating cams, 15,*is shown in Fig. 3. The ordinary valve tappets are shown at 16, extending through vposts, 17, on the housing, 12. n

Each ignitiondevice includes an upper semi-permanent casing, A, extending through the water jacket, 10, a lower removable casing, B, traversing the space between Vthe water jacket, 10, and the crank case, 12, and a sliding firing pin, C. -The upper casing, A, comprises a cylindrical shell, 19,

threaded at 20, throughthe` upper wall of the water jacket, 19, and extending into the explosion chamber, 14, and an inner bushing, 20, insulated from the shell, 19, by means of the porcelain or other suitable insulating material, 21. f

The lower end of the shell, 19, is provided with a squared colla-r, 22, to which awrench may be fitted in inserting the shell, 19, and which also serves to engage a gasket, 23, against the under face of the lower wall of the water jacket, 10, in order to provide a fluid-tight' joint. The shell, 19, extends somewhat below the collar, 22, and is received in the upperend of the casing, B.

The firing pin unit is assembled within a tubular metallic jacket, 24, which is slidingly mounted in the casing, B. The casing, B, atits` lower end is enlarged, asv at 25, to receive a spring,26, compressed between the shoulder formed by the enlargement, 25, and a nut, 27, threaded onto the y end of the acket, 24. t

It may be mentioned at this point that the casing, 24, together with the ring pin, C, are inserted in place from` within the crank case, 12, by 1 being extended upwardly through the opening, 28, provided inthe crank case to receivetlie enlargement, 25.

Fixed within the jacket, 24, by means of the porcelain filling, 21, is the bearing sleeve, 29% f -A tappet, 34is secured by the insulating material, 29, and together with lthe jacket,

24, forms a rigid unitary structure in the i lower portion of the firing pin. Y

Secured on the cam shaft, 18, is a cani, D, comprising a metallic cam sleeve, 35, and the cam proper, 36, The sleeve, 35, is'secured to an enlarged portion, 37, of the cam shaft, 18, by means of a setscrew, 38. Thus the sleeve, 35, may be slipped over the cam, 15,v in removing for repair purposes or in adjusting for timing. The cam ordinarily turns in the direction indicated by the arrow in Fig. 1, and in the lifting` face of the cam is inserted a collar of insulating material, 39, extending to a point just short of the peak of the cam.

f The firing pin, C, is held inengagement with the cam, D, by means of a spring, 26, only the tappet, 34, being in contact with the face of the cam. The firing pin electrode, 40, is provided at its lower end with a binding post, 41, and a. nut, 42, to receive an electrical connection, 43. The lower end of the electrode, 40, is secured in the insulating material, 29, and t-he upper. endr slidably mounted in the sleeve, 29a. The tappet, 34, is likewise provided with a binding post, 44, anda nut, 45, securing a conductor,l46. Current, may be supplied from any source ofy high tension current, such as the induction coil 47, actuated from a source of low tension current, 48, and having its secondary connected to the tappet, 34, and electrode, 40, through the incdiuni of the conductors, 43 and 46, respectively.

It will be understood that the coil, 47 supplies current to each of the several vignition devices which are connected in parallel, all of the electrodes, 40, being connected to the conductor, 43, and all of the tappets, 34, being connected to the conductor, 46.

I provide an upper electrode, 49, which is mounted for sliding movement against spring pressure as follows. A hollow plug, 50, is threaded at 51 into the upper wall of the chamber, 14, and has a polygonal head,

52, to which a wrench may be fitted, and

which yengages the upper surface of the en- `gine head through the medium of a gasket, 53, serving to secure the plug in engagement with the cylinder head.

A headed bushing, 54, is threaded into the upper open end of the plug, 50, and is provided with an opening through which the electrode, 40, is slidingly received. Between the lower face of the bushing, y54, and a shoulder, 55, formed on the electrode, 49, is a spring, 56` tending to urge the electrode, 49, downwardly. The upper end of the electrode, 49, is threaded to receive an adjustable head, 57, adapted to engage the prongs, 5S, of a pivoted timing fork, 59, and thus to limit the down movement of the electrode,

The fork, 59, is mounted on a shaft, 69, extending longitudinally of the engine through brackets, 61, and oscillating movement is transmitted through the shaft, 60, to the fork, 59, by means of an arm, 62, fixed tothe shaft, 60, and a link, 63, extending from the arm, 62, to the ordinary spark control shaft of the vehicle.

It will now be seen that as the cam, 36, is rotated, as indicated by the arrow, the insulating face, 39, will first engage the tappet, 34, and break the connection therewith to the engine housing. The firing pin will then be raised through the medium of the tappet until the lower electrode, 49, has either appreached within firing distance of the upper electrode, 49, or has rengaged it as shown in Fig. 1, at which time contact will be established through the two electrodes between the induction coil and the engine housing. Vhen the peak of the cam reaches the tappet, 34, the circuit will be completed through the tappet, 34, and the cam shaft, 18, to the engine housing, and after the electrodes are then spaced apart a spark will occur at that point. After the electrodes are in contact the spark will occur when the cam has rotated sufficiently to allow the electrodes to separate.

The parts are preferably arranged so that when the spark lever is in extreme advanced position the fork, 58, will lift the upper electrode, 49, to such a point that the lower electrode, 40, will merely contact with the upper electrode, 49, without lifting it any appreciable distance. Thus when the engine is running at high speed the action ofthe ignition device will be smoother than if the upper electrodes were being lifted appreciably.

' Vf hen the spark lever is retarded the fork, S, will be lowered to such a position that the electrode, 49, will be raised a considerable distance by the tiring pin has r ceded substantiallyrlhus the points will not separate until the cam, 36, has traveled a distance considerably beyond the point shown in l, so as to lower the firing pin, and the spark will thus occur at a later time.y

The parts may be so arranged that the electrodes will merely approach within tiring distance and then recede when the spark is advanced position, although one dis-ad vantage in such an arrangement lies in the fact that the spark would also tend to occur between the cam and the tappet, 34,

and to burnout the insulation, 89. Y

l have found Yfrom experiment that where the Firing pinis constantly grounded to the engine such premature tiring will occur and that good results arey not obtained thereby. l attribute this to the fact that the resistance of the circuit will` vary under varying conditions ot lubrication, or" the strength of current applied to the induction coil,` and of possible clogging' to a certain extent of the electrodes by carbon or other foreign material. Under these varying conditions oi' resistance the arc will not be establishec at accurately regular intervals. That is', at some times it will occur too soon, and at other times too late.

By bringing the electrode, 40, within a certain predetermined distance, much less than that at which an arc would ordinarily commence, and then grounding the tiring pin to the trame of the engine, it^w`illfr be seen that the time of the spark can be much more accurately controlled. rlhis is attained by insulating the cam, 5G, during that portion oit the rise in which the electrede, 42, is brought to the proper position relative to the stationary electrode, 16.

Upon contact of the tappet, 34, with theV portion, '36, a circuit will be completed through the ring pin, C, the body of the engine, and the induction coil, 47.

ln the form here shown the actual spark will not occur until the tappet has passed the hump ot the cam. The spark will then occur upon separation ot the points.

I nd that there are some advantages in allowing the electrodes to actually contact at all times. For intance, the contact of the electrodes helps to keep the faces thereof clean, and in some cases a direct low ten may further be adjust-ed from the exterior iii of the engine by rotating the threaded not received onthe upper end of the casing, l5,

andengaging the lower wall ot the water p jacket, 10.

- In order to allow access to the ends ot the electrode and tappet, vthe casing, B, and

the jacket, 24, are apertured, as shown inV Fig. l.

ln order to adjust the timing the cam, D, may be rotated on the shaft, 18, and secured in the proper position by means of the set screw, 38. Where the ordinary cam shaft is used the cam, D, may be formed in two sections, or made large enough in diameter to slipy over the valve raising means as shown. l l

ln Fig. 4, I have shown a slightly ditlierent arrangement of the parts of the electrical circuitr and upper contact member, lin which the contact, 49a, is insulated by means of an insulating sleeve, 49h, slidably mounted in the fork, 50, in the same manner that the electrode, 49, is mounted in the plug, 50. The head, 57a, is threaded to the upper end of the insulating sleeve, 491. The upper end ofthe electrode, 49a, is threaded and provided with nuts, 49C, and 49, to receive a connector, 49e. A portion ot' the upper end of the lower electrode, 40, is illustrated. in the diagram, and a portion of the loi'i'cr end of the tappet, 34.V The twoA are corr nected as indicated at 492 by some form of connector, replacing the wires, 43 and 46. One side of theinduction coil secondary is grounded, as at 49g, and the circuit is thus completed through the engine housing, induction coil, the connector, 49e, the electrodes, 49, and 40, the tappet, 84, and the cam, 36, when the hump of the cam is reached.

ln order to prevent rotation of the firing pin relative to the casing, B, a small screv, 64, is secured in the jacket, 24, and slidably eBXtended through the slot., 65, in the casing,

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the vreal spirit and purpose of my invention, and

it is my intention to cover by my claims any lun niodiiied forms of struct-ure or use ot niechanical equivalents which may reasonably included i'ithin their scope.

I claim as my invention:

Vl. In combination with an engine liousin having an explosion chamber, afcam shaft journalled in Vsaid housing, a cam on the shaft having a bearing face insulated during a portion of its periphery from they cam shaft and electrically connected thereto during the remainder of its peripher a firing pin slidably mounted relative to the housing and insulated therefrom, said iiring pin having `an end extending into the. explosion chamber and its other end engaged against the cam, an electrode supported in the engine housing above the tiring Jin, and a rcircuit including a source of high tension current, said electrode, and the engine housing, the cam inrotating serving first to establish electrical communication between the firing pin and electrode, then to complete the circuit by grounding the iiring pin to the engine housing, and then to break the circuit between the tiring` pin and electrode while maintaining the tiring pin in grounded relation to the engine housing.

2. In combination with an engine housing` havingl an explosion chamber, a cam shaft journalledin said housing, a cam on the shaft having a bearing 'face insulated during a portion of its periphery from the cam 'shaft and electrically connected thereto during the remainder of its periphery, a firing pin slidably. mounted relative to the housing and insulated therefron'i, said tiring pin having an end extending into4 the explosion chamber and its otherend engaged against the cam, an electrode supported in the vengine housing above the firing pin, and a circuit including a source of high tension current, said electrode, and theengine housing, the cam in rotating serving iirst to establish electrical communication between the iring pin and electrode, and then to complete the circuit by grounding the tiring pin to the engine housing. 1 Y n 3. In combination with an engine housing having an explosionchamber, a firing pin mounted relative to the housing for sliding" movement, and having an end extending into the explosion chamber, an electrode supported in the engine housing above the tiring pin, a circuit including a source of high tension current, the clectrode,-the iiring pin andthe engine housing, and means serving iirst to establish electrical communication between the tiring pin and electrode, then to complete the circuit by grounding the tiring pin to the engine housing, and then to break the circuit between the tiring pin and electrode while maintaining the .tiring pin'in grounded relation to the cnginehousing.

4. In combination with lan engine housing having an explosion chamber, a firing pin mounted relative to the'housing for sliding movement, and having an end extendingv into the explosion chamber, an electrode supported in the engine housing above the firing pin, a circuit including a source of high tension current, the electrode, the firing pin and the engine housing, and means serving irst' to establish electrical communication between the iiring pin` and electrode, and then to complete the circuit by grounding the iiring pin-to the engine housing.

Y5. In combination with an engine housing having an explosion chamber, a ringpin mounted relative to the housing for slidingr movement, and havingY an end extending into the explosion chamber, an electrode supported in the engine housing above the tiring v pin, means for adjusting said electrode toward or from said firing pinfso as to retard or advance the moment of firing between said electrodes, ay circuit including a source of high tension current, .the electrode, the tiring pin and the engine housing, and means serving iirst to establish electrical communication .between the tiring pin yand electrode, and then to complete thecircuit by grounding the tiring pin to the engine housing.

Signed at kSioux City, in the county ot Woodbury and State of Iowa, this 26th day ot February, 1925. Y

CLARENCE IV. BARNES. 

